LOS ANGELES — A heavily drugged man wearing a 6-foot-long boa constrictor around his neck led police on a three-hour chase that ended after he rammed his car into a Highway Patrol car, authorities said today.

Steven P. Moore of Lake View Terrace had been chased from the northern San Fernando Valley by police who suspected that he had assaulted a woman with an ax handle.

The chase ended late Sunday at the Cheseboro Road exit of the Ventura Freeway in Agoura Hills, Lt. Jim Watters said. Moore was arrested and booked on suspicion of assaulting a police officer with a deadly weapon and was treated for drug ingestion at County USC Medical Center.

During the 186-mile pursuit, Moore allegedly drove at speeds exceeding 100 m.p.h., sped the wrong way on freeways in an attempt to elude police and tried unsuccessfully to back into other cars, Watters said.

Several officers reported seeing a large snake wrapped around the man's neck during the chase. The boa constrictor, a family pet, was found in the back seat of Moore's car and was put in an animal shelter.